Overlaid display of, for example, hand-drawn drawings on video images during video image playback has been performed hitherto. For example, a live streaming broadcast method for broadcasting live over a network has been proposed. In this live streaming broadcast method, at the same time as camera footage data is being input, other footage data such as hand-drawn drawing data is combined with the camera footage data that is being input.
Moreover, a system has been proposed in which a lecturer computer displays necessary lecture materials, and also displays captured images of a lecturer captured using a camera combined with hand-drawn image data from a tablet.
A system for playback of a digital stream stored on a recording medium has also been proposed. The digital stream is obtained by multiplexing a video stream and a graphics stream of subtitles or the like.
Technology has also been proposed for managing image data associated with footage captured using an imaging device, and vector data obtained by performing moving object extraction processing on the footage. In this technology, vector data expressing a graphic representing a position and size of a moving object obtained corresponding to image data is connected to the end of the image data of each frame, and transmitted to a video display device. Every time image data of an individual frame is received from a video data management device, the video display device performs display processing based on the image data of that frame. Then, line drawings expressing the graphic generated based on the vector data are added on top of an image reproduced based on the image data.